With the popularity of Internet technologies, the number of terminal devices increases rapidly, and each terminal device needs to obtain a valid Internet protocol (IP) address (such as, IPv4 address) when communicating with the Internet; therefore, valid IP addresses become scarce resources. To solve insufficiency of valid IP addresses, a built-in or an external network address translation (NAT) device on a gateway device may be used to establish NAT entry information, so as to translate a group of IP address information into another group of IP address information, for example, translate a group of private IP addresses (such as, IPv6 address) and private network port numbers of a local area network into valid IP addresses (such as, IPv4 address) and public network port numbers of the Internet.
A policy and charging control (PCC) architecture defined by the 3rd generation partnership project (3GPP) may be mainly formed by an application function entity (AF), a policy and charging rules function entity (PCRF), and a policy and charging enforcement function entity (PCEF). The PCRF receives application-layer session information that is dynamically provided by the AF, generates corresponding PCC rules according to the session information, and delivers the PCC rules to the gateway device, so that the gateway device executes these PCC rules.
However, after the NAT device is introduced, the AF can only identify an IP address (such as, IPv4 address) obtained through translating by the NAT device, while the gateway device can only identify an IP address (such as, IPv6 address) to be translated by the NAT device; therefore, after the PCRF generates, according to the session information of the AF, a PCC rule including the IP address obtained through translating by the NAT device and delivers the PCC rule to the gateway device, the gateway device cannot identify the IP address in the PCC rule, thereby causing that the gateway device cannot execute the PCC rule.